Organopolysiloxanes containing amino groups have been used heretofore as textile finishing agents. Good soft handle effects are obtained with the textiles treated with these agents. However, the amino-functional group --(CH.sub.2).sub.3 NHCH.sub.2 CH.sub.2 NH.sub.2 preferably used heretofore shows a strong tendency towards thermal yellowing, a discoloration of the treated fibers which is accelerated by elevated temperature.
The reduction of thermal yellowing by reaction of the organopolysiloxane comprising amino groups with organic epoxides is described, for example, in EP-A-399 706 (S. E. Cray el al., published Nov. 28, 1990 for Dow Corning Ltd., Great Britain). However, the effect achieved in this manner is not sufficient.
A more effective manner of achieving a reduction in thermal yellowing is by reacting with acylating agents, such as carboxylic acids and anhydrides thereof, such as described in, for example, EP-A-349 753 and EP-A-349 754 (M. Ozaki et al., published on Jan. 10, 1990 for Toray Silicone Co., Ltd., Japan). Further acylating agents for reducing thermal yellowing are lactones, the use of which for modifying aminosilicone textile treatment agents is disclosed in, inter alia, EP-A-342 830 and EP-A-342 834 (S. E. Cray et al., published on May 5, 1989 for Dow Corning Ltd., Great Britain), carbonates, the use of which is disclosed in JP-A-90/47371 (S. Yokoyama et al., published Feb. 16, 1990 for Kyoeisha Yushi K.K. AG, Japan) and oxalic acid esters, the use of which is disclosed in U.S. Pat. No. 5,039,738 (A. M. Czech; issued Aug. 13, 1991 for Union Carbide Corp., USA).
However, the acylating agents reduce the soft handle effect of the treated textiles, especially in the case of high degrees of acylation.
In addition to the soft handle effect, a few desirable properties of the treated textiles, such as resilience and crease recovery, are improved by the elastomeric properties of the aminosilicone textile treatment agents.
The use of epoxy-functional trialkoxysilanes as crosslinking components in an aminosilicone textile treatment agent is disclosed in EP-A-358 329 (K. Spyropolous; published Mar. 14, 1990 for Dow Corning Ltd., Great Britain). The use of epoxy-functional silanes and additionally organic epoxides is described in U.S. Pat. No. 4,757,121 (M. Tanaka et al., published Jul. 12, 1988 for Shin-Etsu Chemical Co., Japan). An elastomeric character of the textile treatment agents is indeed obtained in both cases, but the reduction in thermal yellowing is not sufficient.
The reaction of an organopolysiloxane comprising amino groups with acetic anhydride and epoxy-functional silanes is disclosed in JP-A-87/41379 (T. Yasukawa et al., published Feb. 23, 1987 for Nikka Chemical Industry Co., Ltd.). The resulting amino-silicone textile treatment agents are, however, only a compromise solution between good crosslinkability and reduction in thermal yellowing since the epoxy-functional silane makes only little contribution to the reduction in thermal yellowing and acetic anhydride makes no contribution to crosslinkability.
Therefore, it is an object of the present invention to provide a crosslinkable composition containing an organopolysiloxane having amino groups. Another object of the present invention is to provide a crosslinkable composition containing an organopolysiloxane having amino groups which can be used as a textile finishing agent. Still another object of the present invention is to provide a crosslinkable organopolysiloxane composition containing an organopolysiloxane having amino groups from which a textile finishing agent can easily be prepared. A further object of the present invention is to provide a crosslinkable composition containing an organopolysiloxane having amino groups which provides good crosslinkability and good reduction in thermal yellowing.